Fuel pump



THOMAS `ill7JDlLJE |E{lll\l'(.'1r S,v OIF CHICAGO, JEILLTNOIS, 'ASSIGNOR TO INTERNATJEONAJL i JEIVESTER COMPANY, A CORPORATION OIFNEW J' This invention'relates to fuel pumps and l particularly to pumps for injecting fuel into the cylinders of high compression linternal combustion engines. .I 'i i @ne requisite of such pumps is thatthey start the stream of injected oil very sudstroke, and that they stop the injection just as suddenly to prevent dribbling the oil on the cylinder walls. The economy of the engine depends in great measure'on the rformance of the pump and its vability todeliver a definite quantity of oil at a definite vtime and in a definite way.

An object of this invention is to provide a fuel pump which'will meet the above requirements. l f

Another object is to provide a fuel pump which can suddenly start and stop the streamof injected fuel with a means for' automatically controlling t-he injection of the 3o fuel.

These and other objects are accomplished by my invention which comprisesa i fuel pump having a cylinder, aplunger operablev therein, `a compression space beneath said plunger and mea-ns fo'r maintaining the vol- .-ume of said compression space substantially constant for a part of the stroke of said plunger and means for suddenly decreasing the volume of said compression space.

Referring now to the drawing, the ligure represents. a vertical sectional view of my fuel pump. The body of the pump 10 has l slidably fitted therein a plunger 11 which normally acts against the compression spring 12. Below the plunger is the usual compression space 13 which communicates with inletvalve 14 and the delivery valve 15, the latter being normally held on its seat by the spring 16. pipe 17 leads-from the main reservior or source of fuel supply to the pump, and the pipe 18 leads from the delivery valve to the engine cylinder or other part to which fuel is to be supplied. Communicating with the compression space is a follower 19 which is slidable in the auxiliary .Application filed .Tune 9,

denly and ata deinite timev in the ypiston preferably communicates with ima. seriainuf maar?.

cylinder 20, the follower being normally held upon the stop 21 by a'spring 22, which, however, lisof such a strength that Yit will yield to a pressure which is insuflicient tol force the delivery valve 15 0H its. seat. VA 60 plug 23 which also forms a stop isplaced f above the follower 19. This plug `has avent 24 to allow of easy access of the air-4 to the top of thev follower. It will thus be seen that the movementof the follower may be adjusted by adjusting the heights of the sto 21 and the plug-23. nother extension -of. the compression.

space 13,1eadsto the by-pass valve 25.which opens communication` with an auxiliary resf. ervoir 26 which is formed byplacing a wall 27 about the-upperpartof the pump. `This 'reservoir has an overflow pipe 28` which.y

the main fuel supply tank (not shown). The byfpass -valve 25 is normally held on its seat by means of a Spring 29 which is relatively stier than springs 16 and 22,"so thatthe bypass will 4never be forced from its seat by pressure from within the compression space 13.

The plunger 11 is actuated by means of an eccentric 30 and eccentric strap 3 1 which is pivotally connected at 32 to a rocker arm 33, which in turn is pivotally mounted upon an eccentric 34 which is carried on a bearing 35 on the reservoir wall 27. The -opposite end of the rocker arm 3 3 carries a finger 33a which engages the underside of a nut 36 onthe stem 37 of the by-pass valve 25. The 90 eccentric 34 has an eccentric arm` 34a which is operated by means of a rodl 38 from .a govvernor 39. A11 operating lever 40 is pivoted at 41 to the reservoir wall to provide a means of operating the plunger llby hand. linV operation the plunger l1 draws liquid from the reservoir (not shown) through the inlet valve 14. `As this-valve closesand the plun` ger descends, the fuel in the compression space 13 forces the follower 19 away from .100 the stop 2l against which it normally rests.

f As the plunger 11 descends, the follower 19 will be forced up, keeping the compression space 13 constant and the pressure substantia-ily so until the up er part -of the fol 105 lower 19 strikes the p ug 24, when it will' come to a sudden stop, which is the position of the art shown in the figure of the drawing. lloreover, l have preferably shown this action as taking place at the time when 119 the plunger 11 is substantially at the centerY of its stroke, when -it is moving with the greatest rapidity. The effect of suddenly decreasing the compression space, therefore, due to the rapid downward movement of the plunger l1, and the sudden stoppage of the i and this I accomplish by means of the finger 33 of the rocker arm 33, which suddenly lifts the by-pass valve 25, forcing the remainder of the fuel due to the stroke of the piston l1 into the reservoir 26. The point at which the by-pass valve will open may be adjusted by' means of the nut 36 and the parts which go to make up the governor controlled mechanism. y

Fuel pumps of this kind are intended primarily for use on high compression internal combustion engines where the fuel is injected directly intovthe cylinder. It is very essential that the time during which fuel is injected is very small, but this time can be very accurately predetermined, and this it will readily be seen I have accomplished by my invention. j

Vhile I have shown and described but a single embodiment of my invent-ion, it is to be understood that it is capable of modification. Changes, therefore, in the construction and arrangement of parts may be made which do not depart from the spirit and scope of the invention as expressed in the following claims:

l. In a fuel pump for internal combustion engines, the combination of a pump cyl inder having a compression space, a piston in thecylinder driven from the engine, intake and discharge valves for the cylinder, a follower slidable in a bore in communication with the compression space, adjustable means for limiting the movement of the follower, a by-pass valve, means for opening the by-pass valve, and means controlled by thespeed of the engine for determining the point at which the by-pass valve is opened.

2. In a fuel pump for internal combustion engines, the combination of a ypump cylinder having a compression space, a piston in the cylinder driven from the engine, intake and discharge valves for the cylinder, a follower slidable in a bore in communication with the compression space, adjustable means for limiting the movement of the follower, a by-pass valve, means for opening the by-pass valve, and means wholly independent ofthe follower limiting means for determining the point in the stroke of the piston at which the by-pass valve is opened.

rIn testimony whereof I aiiix my signature.

THOMAS WILLIAM KINGS. 

